Device means for a vehicle in a warehousing apparatus

ABSTRACT

Warehousing system apparatus has a storage rack with several vertically and horizontally related storage elements. A mast is moved horizontally on rails parallel to the face of a storage rack, and a platform moves vertically along the mast in response to signals from a three-brush signal wire pickup on a control wire strung along the rack. Vertical and horizontal hydraulic drives and controls are independent so that the platform may fly or move diagonally in the shortest line between locations in the storage rack. Electric motors constantly operate hydraulic pumps; pump output is controlled by stepping motors having telemetering switches to indicate pumping direction. A positive neutral band is provided in the hydraulic system for better drive control. A carrier which is driven from the platform into the rack has a cam means to change the position of load driving lugs each time the carrier is driven to a maximum displacement from the platform.

United States Patent 1 1 Richens et al. 1 1 Jan. 2, 1973 [54] DEVICEMEANS FOR A VEHICLE IN A 3,230,699 1 1966 Hann etal. ..60/53 AWAREHOUSING APPARATUS 3,352,978 11/1967 Hartman ..2l4/16.4 A 3,406,84610 1968 oc ..214 16.4 A [75] Inventors? Kennelh Richens, Salli Lake Y3,486,092 12/1969 ..214/16.4 A

Scott C. Grover, Bountiful; James Anred, Salt Lake City, of PrimaryExaminer-Gerald M. Forlenza Utah; James s Lakewood, AssistantExaminer-11. B. Johnson C010- Attorney-Teagno & Toddy [73] Assignee:Eaton Yale 8r Towne Inc., Cleveland, Ohio [57] ABSTRACT [22] Filed; June11, 1971 Warehousing system apparatus has a storage rack with severalvertically and horizontally related storage ele- 2 PP 152,302 ments. Amast is moved horizontally on rails parallel to the face of a storagerack, and a platform moves Related Applicauon Data vertically along themast in response to signals from a [62] Division of Ser. No. 832,036,May S, 1969, Pat. No three-brush signal wire pickup ona control wire,001. strung along the rack. Vertical and horizontal hydraulic drivesand controls are independent so that the [52] US. Cl. ..2l4/16.4 A,60/53 A platform may fly or move diagonally in the shortest [51] Int. Cl..B65g 1/06 line between locations in the storage rack. Electric [58]Field of Search ..2l4/l6.4 A; 60/53 A, 60 VS motors constantly operatehydraulic pumps; pump output is controlled by stepping motors havingteleme- [56] References Cited tering switches to indicate pumpingdirection. A positive neutral band is provided in the hydraulic systemUNITED STATES PATENTS for better drive control, A carrier which isdriven from 2 941 4 0 19 the platform into the rack has a cam means tochange 2,988,237 6/1961 the position of load driving lugs each time thecarrier 3,049,247 8/1962 is driven to a maximum displacement from theplat- 3,139,994 7/1964 form. 3,196,616 7/1965 3,212,263 10/1965 10Claims, 12 Drawing Figures S ITCHING 234 2 v w 236 294 DEVICE 9 296 242240\ HORIZSNTAL 244 LEFT OR VER1!ICAL 112i Gears, sales? 238 gi cuir aw.DRIVE CIRCUIT 259 250 l 252 DIRECTION VARIABLE 254 24s 25s VAR'ABLED'RECTON TELEMETERING" ggg igg 2 25;? g u r k L k TELEJMETERING 25th 212L; 7 r hh rgi I PUMP t PUMP ELIEOCTTgEC NULL NULL V W L 282; l ena DiscHYDRAULIC 7: HYDR ULI DISC BRAKE MOTOR MOTOR BRAKE PTOTRTZCSQ FAI DRIVEvmncn DRIVE VERTICAL ROTARY TRANSDUCER PLATFORM PATENTEDJAN 2191a sum 7BF 8 u QMR Ll NN 2: m2

A ll III II N 1 \41 llilllll 1 LF LP. KIL R|EI@HIEJ W h u +1 k mow m2 inAU N2 Ee /W V mom 06 wow NE wow wow wow k DON PATENTEDJM 21913 SHEET 8[1F 8 mwh3a 200 DEVICE MEANS FOR A VEHICLE IN A WAREHOUSING APPARATUSThis is a division of co-pending application Ser. No. 832,036, filed May5, 1969 now US. Pat. No. 3,632,601 granted Jan. 4, l972.

BACKGROUND OF THE INVENTION Warehousing systems have come into wide use,and much attention has been given to the development of fast, accurateand dependable warehousing equipment which operates automatically withvery little human supervision. High costs associated with conventionalwarehousing and needs for rapid systems have speeds commensurate withimproved mass production, rapid transportation, and inventory controltechniques have required more automated systems. Many warehousingsystems have several rows of storage racks which are supplied by inputand output conveyors near ends of the racks. Stacker-retriever apparatusis located in each aisle between the racks to take goods from an inputconveyor, to carry the goods to a particular location in the rack, toinsert the goods in the racks, and to withdraw the goods from the racks,to carry them to the output conveyor, and to deposit them thereon as inother words, perform an automatic warehousing function. Control of theinput and output conveyors and control of the stacker-retriever iseffected by a remote computer. The computer is connected with thestackerretriever either by physical inner-connection or by radio wavesto control the movement of operation thereof.

Other warehousing systems which employ'stackerretrievers have a singlerack face on one side of an aisle which is serviced by astacker-retriever. On the other side of the aisle several stations withcontrol consoles are provided to signal the main control computer as tothe appropriate disposition of a load placed at the station, that is itsappropriate storage place in a rack, or the storage place in a rack fromwhich a load is desired to be deposited at the station.

Other warehousing systems which employ stackerretrievers have a singlerack face on one side of an aisle which is serviced by astacker-retriever. On the other side of the aisle several stations withcontrol consoles are provided to signal the main control computer as tothe appropriate disposition of a load placed at the station, that is itsappropriate storage place in a rack, or the storage place in a rack fromwhich a load is desired to be deposited at the station.

For convenience, the present invention has been described as in use withthe latter form of warehousing system. It is obvious however, that thestacker-retriever which is described herein has equal application foruse with a multiple aisle input and output conveyor system. Well knownauxiliary apparatus transfers loads between conveyors and a stackerplatform having a carrier configured to drive loads or to draw loadslaterally off or on the platform.

Many problems remain in stacker-retriever technology. Because masts arevery tall, acceleration and deceleration control are very important.Wear of mast supporting rails and rollers caused by driving frictioncauses rough travel and inaccuracy in the positioning of loads.Complexity of cycling circuitry and mechanical 'driving apparatus forshuttles inserters is another problem. Additionally, communicationsbetween a stacker-retriever and a main control console are difficult.

SUMMARY OF THE INVENTION The present invention solves problems instackerretriever technology by providing a hydraulic drive apparatuswith unique acceleration, deceleration and positioning controls.Problems associated with wear are avoided by driving and supporting themast with mutually distinct surfaces. Inserter circuitry complexity islimited to starting an electric motor in either direction. Accuratecommunications are insured by a three brush link.

While a preferred form of the stacker-retriever is described in detailherein with a mast carriage moving on floor mounting rails, all of thebenefits of the invention are achieved by supporting the mast onoverhead rail and driving the mast on separate overhead surface. Whilethe invention described herein in the detailed portion of thespecification discusses a preferred embodiment in which both horizontaland vertical drives are electrohydraulically operated, it is obviousthat either of the independent drive systems may be operated in aconventional manner.

One object of this invention is the provision of hydraulic driveapparatus with smooth acceleration and deceleration which is controlledby counters.

Another object of this invention is the provision of means forcontrolling acceleration drive and deceleration of horizontal andvertical stacker-retriever components in a warehouse system.

Another object of this invention is the provision of drive apparatus fora stacker-retriever which is independent of support surfaces for themast.

A further object of this invention is the provision of mechanicallycycled inserter apparatus for stackerretrievers in warehousing systems.

Another object of this invention is the provision of redundant input andoutput signal pickups for warehousing communications systems.

These and other objects of the invention will be apparent from thespecification which includes the claims and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view ofwarehousing system apparatus of the present invention, showing thegeneral relationship of the stacker-retriever, storage racks and stationelements.

FIG. 2 is a side elevation of a stacker-retriever of the presentinvention.

FIG. 2A is a cross-sectional detail of a signal wire pickup.

FIG. 3 is an elevational detail partially in cross-section, showing thearrangement of the driving apparatus of this invention.

FIG. 4 is a side elevational detail partially cutaway view of theapparatus shown in FIG. 3.

FIG. 5 is an end elevational detail of a roller assembly which isemployed in the present invention.

FIG. 6 is a side elevational detail of the roller assembly shown in FIG.5.

FIG. 7 is an end elevational of the platform which is vertically movableto selected storage and station locations.

FIG. 8 is a side elevation of the platform and carrier, showing thecarrier in an extended position of maximum lateral displacement from theplatform.

FIG. 9 is a side elevation detail of a camming mechanism for raising andlowering the load engaging lugs.

FIG. 10 is a plan view detail of the apparatus of FIG. 9.

FIG. 11 is a schematic flow chart representation of the operationalinterrelationship of parts of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIG. 1, a warehousingsystem apparatus is generally referred to by the numeral 1. Astackerretriever 2 comprises a mast means 4, including a carriage 6.Mast means 4 and its carriage 6 move along parallel rails 8, which aremounted on the floor 9 of warehouse parallel to the face of a storagerack 11. Storage rack 11 defines a plurality of load bins 12 andincludes a plurality of vertical columns 14 and horizontal shelves 16.Each bin 12 has horizontal shelves 16 which are spaced from each other,defining a central opening 18 therebetween.

Moving mast means 4 and its carriage 6 along rails 8 aligns loadplatform 20 on stacker-retriever 2 adjacent a vertical row of storagebins 12. Platform 20 is raised and lowered on mast 4 to align theplatform 20 with a specified shelf of the storage bin. Movement may beaffected in vertical and horizontal directions simultaneously, so thatthe platform 20 may fly or move in a diagonal direction adjacent theface of storage rack 1 1. When platform 20 is aligned at the appropriatebin 12, a shuttle mechanism 22 is driven transversely to rails 8 andmast 4 into the storage bin gap 18 between shelves 16. If a load is onplatform 20 as it approaches the designated bin, lugs 24 of the shuttle22 are in an up, load-engaging position. As shuttle mechanism 22 isdriven into the storage rack, lugs 24 which are in the up position drivethe load into the rack. As soon as shuttle mechanism 22 approaches anextended position from platform 20, lugs 24 are cammed downward into aload-passing position in a manner to be described hereinafter, andshuttle 22 is withdrawn into platform 20 with lugs 24 remaining in thedown position. Platform 20 is then ready to be relocated adjacent a nextdesignated station, whereat shuttle mechanism 22 is driven into thestation with lugs 24 in the downward position. As the shuttle mechanism22 approaches the extended position, lugs 24 are cammed to an upwardload-engaging position. As the shuttle 22 is withdrawn onto theplatform, lugs 24 engage and pull the load onto the platform.

The warehouse system 1 includes a load pickup station 30. The pick-upstation 30 includes parallel shelves 32 which are spaced from each otherleaving a gap 34 therebetween through which shuttle mechanism 22 moves.A control station 36 with buttons 38 programs a main control console,not shown, by designating a bin 12 from which a load is to be picked upfor placing on shelves 32, or by designating the locus of a bin 12 towhich a load from shelves 32 is to be returned.

FIG. 2 describes the stacker 2 in more detail. Mast assembly 4 issupported by carriage 6, riding on rails 8, which are fixed to floor 9.Platform 20 is selectively driven up and down mast 4 between lower andupper limits of the platform 20 as shown in phantom lines. Shuttlemechanism 22 and lugs 24 move transversely to the plane of the drawing,sliding loads on and off platform 20 between a pair of load guides 26.The latter are provided to insure that a load is centered on theplatform 20 or in the appropriate bin 12 in the storage rack 1 l as theload is being slid on and off platform 20.

Electrical power is supplied to the stacker by an umbilical cord lyingin a specially provided channel on the floor 9. Alternatively, power maybe supplied to the stacker via the rails 8 or through a third railpositioned between the rails 8 and preferably below floor level in amanner which is conventional to railway operations.

Control signals are supplied to the stacker 2 by a signal wire 40 whichis strung along the storage rack adjacent an upper extremity of mast 4or which alternatively may be positioned adjacent one of the rails.Signals are picked up from a wire 40 as shown in detail in FIG. 2A. Inmost assemblies single pickups vibrate when moving across a wire,producing spurious signals or interference. The present signal pickupassembly 42 is designed to be interference free. Assembly 42 is mountedon the stacker 2 for movement along the wire 40 so that the wire 40passes through the assembly 42. First, second, and third brushes 43, 44and 45 are arranged in the assembly 42 so that the first brush pressesthe wire toward the second and third brushes 44, 45 which are oppositelymounted with respect to the first brush 43. In a conventional manner,springs 46 insure contact of the brushes 43, 44, 45 with the wire 40.Outputs of the brushes are connected to a common output 48 which carriesthe signal from the wire 40 to the onboard control unit 50. Lights 52may be provided in the control unit to indicate mode of operation,stacker location and destination.

Although the stacker 2 is constructed for automatic operation inresponse to instructions from a computer console at a remote location,the stacker 2 may be driven by an onboard operator. An operators step 54is spring loaded to an upward position. An operator standing on step 54causes the step to be depressed, closing a switch similar to aconventional railroad dead man switch. The switch under step 54 operatesrelays, stopping automatic operation of the stacker and associatedautomatic control apparatus, and permitting the onboard operator tocontrol the stacker 2 in its vertical, horizontal and transversemovements by manually operating switches 56. Pairings 58 insure againstportions of the operators body protruding in the direction of thestorage rack 11. Louvred access door 59 provides access to and coolingfor the electric and hydraulic systems.

Referring to FIGS. 3 and 4 of the drawings, horizontal and verticaldriving 13 effected by electric motors which constantly drive hydraulicpumps, the outputs of which are controlled in positive or negativedirections or at null positions. Outputs of the pumps are connectedthrough delivery lines, which feed hydraulic motors which in turn drivesprockets and chains connected to the vertical platform drive and to themain horizontal driving wheels.

Upper motor-pump combination 60 provides power to drive platform 20vertically along mast 4. klectric motor 61, which is directly connectedto hydraulic pump 62, drives pump 62 at a constant speed. A steppingcontrol motor 63 drives gear 64, which in a well-known manner controlspump configuration and hence the output of pump 62 through intake anddischarge lines 66 and 67. Cams 68 on gear 64 depress telemeteringswitches 70 which feed back pump status information to onboard controlsystem 50. One switch indicates forward operation; the other switchindicates reverse; depression of both switches indicates a null orno-output condition of the pump 62.

Delivery lines 66 and 67 connect pump 62 to inputs of hydraulic motor72, which drives reduction gears located in housing 74. Reductiongearing in housing 74 drives sprocket 76 and chain 78, which isconnected to sprocket 80 on idler shaft 82. Chain 84 in turn drivessprocket 86 on shaft 88. Another sprocket on shaft 88, similar in sizeto sprocket 86, drives chain 90 to which platform assembly is attached,for movement of the platform assembly 20 along the mast 4 thereby.

A disc brake assembly 91 is connected to sprocket 76 to positively lockthe sprocket at various positions which correspond to desired verticalpositions of the platform 20. An umbilical cable harness 92 connects theon-board control unit 50 with an actuator on platform 20. Harness 92 hasa yoke 94, which suspends a weight 96 to maintain the cable harness 92under tension during movement of the platform assembly 20.

The central motor-hydraulic pump system 100 has an electric motor 101which continually turns hydraulic pump 102. Commercially availablestepping motor 103, which has a pulsed rotary output, drives gear 104,which controls the output setting of pump 102. Cams 108 mounted on gear104 selectively close telemetering switches 110, for indication of themode of operation of pump 102, that is, forward, reverse or neutral in amanner similar to that described with respect to motor-pump system 60.

Outputs of pump 102 are connected through delivery lines 106 and 107 tohydraulic motor 112. Hydraulic motor 112 drives reduction gearing inhousing 114, which in turn drives sprocket 116. Sprocket 116 driveschain 118, which is connected to sprocket 120 on main drive axle 122.

Main drive axle 122, hydraulic motor 122 and the reduction gearing aremounted on a lever 124, which is pivoted at point 126 to stackercarriage 6. The normal force between a pair of driving wheels 128 andfloor 9 is maintained constant at a value dictated by the weight ofhydraulic motor 112 and reduction gear 114 and their position on pivotedlever 124, as well as the weight of axle 122, driving wheels 128, chain118 and related equipment. The center of gravity and hence the appliedmovement on lever 124 may be adjusted by changing the position ofhydraulic motor 112 and reduction gear 114 on lever 124. Thus, thenormal force between wheel 128. and floor 9 and, consequently, thefrictional force are controlled and maintained constant, regardless ofthe weight of the stacker, including the mast 4, carriage 6, platformassembly 20, load and related equipment. Driving wheels 128 do not wearthe rails 8 with frictional contact. Moreover, the weight of the stackerassembly and its load are born entirely by roller assemblies 130, whichsupport the stacker 2 on parallel rails 8. Alignment of the stackerassembly relative to the rack 11 is consequently, not influenced by wearbetween driving surfaces.

Roller assemblies 130 which are illustrated in greater detail in FIGS. 5and 6, are provided at each of the four corners of carriage 6. Eachassembly comprises a downward opening U-shaped member 132 which iscentrally connected to carriage frame 6 by bolt 134. Pin 136 mediallyspans parallel flanges 138 of the U- shaped member 132. Parallel crosspieces 140 are mounted for rotational movement of pin 136 interiorly offlanges 138, and rollers 142, which are the principle support of thestacker 2, are mounted at opposite ends of cross members 140. Theinteraction of flanges 138, pin 136 and cross pieces 140 distributes theweight on each assembly equally between the two rollers 142.

To insure proper alignment on track 8, wheels constructed of camfollowers 144 are: connected to extensions 146 on flanges 138, so thatthe wheels are spaced slightly away from lateral edges of track 8. Toinsure against lateral or fore and aft tipping of the tall mastassembly, auxiliary rollers 148 are connected to flanges 138 beneathrail 8. Although any form of auxiliary rollers is suitable andeconomical for use as wheels 144 and 148 of roller assemblies 130.

Beside disc brake assemblies such as 91 which are connected to drivinggears to lock the vertical and horizontal driving apparatus, caliperbrakes which engage upper and lower surfaces of the tracks may bemounted on roller assemblies 130 or elsewhere on carriage 6 to beoperated to lock stacker 2 on the rails 8 and to prevent horizontalmovement when an appropriate location has been reached.

Referring to FIG. 7, a drive mechanism generally referred to by thenumeral 150 is provided on platform 20 for driving shuttle 22, lugs 24,and, hence, load 151 away from the platform or back towards the platformonce platform 20 has been aligned with an appropriate rack element.Guide wheels 26 align load 151 on platform 20; skate wheels 152 providefriction free movement of load 151 across platform 20.

As shown with further reference to FIG. 8, motor and reduction gearmeans 154 drive a pinion gear 156, which in turn drives rack 160. Shafts162 are mounted transversely and medially in rack those shafts terminatein rollers 164 located in grooved rigid lateral supports 166. Pinions168 are loosely mounted on shafts 162 so that moving rack 160 with gear156 moves pinions 168 across a toothed surface of stationary rack 170,which is fixed to the platform assembly 20.

The turning of pinions 168 by moving them across rack 170 causes thepinions to drive second movable rack 172 in the same direction as rack160. As is conventional in such interleaved rack and pinion actuators,rack 172 moves twice the distance of rack 160. Transversely mounted inrack 172 are three shafts 174. Each of these shafts carries rollers 176which are mounted in corresponding grooves of stationary lateralsupports 166 to provide support for rack 172. The central shaft 174mounts a pinion 178 which meshingly engages the upper teeth of rack 160,turning the pinion and thereby driving a third rack 180 which isdirectly connected to the shuttle 22.

The construction of rack 180 and its relationship to rack 172 causes anoperational change of position of lugs 24 as is more clearly shown withreference to FIGS. 9 and 10. Rack 180 of shuttle 22 has bolted theretoand spaced from an upper surface thereof, two hold-down blocks 182.Spacer blocks 184 and bolts 186 join rack 180 and upper bar 182. Pins188 are mounted at remote ends of hold-down bars 182, and lugs 24 arepivoted on pins 188. Blocks 184 act as guides for the actuator bars 190which are received in slots 192 of lug actuator bars 190. Pins 194 aremounted in the outer ends of actuator bars 190 and links 196 areconnected to those pins. The remote ends of links 196 are connected topins 198 which are mounted in the lugs 24. When actuator bars 190 are intheir outermost position, pins 198 are forced outwardly about pins 188,causing lugs 24 to pivot upwardly about the latter pins. When bars 190are in their innermost position, pins 198 are pulled forwardly about pin188, drawing lugs 24 downward to their load-passing position.

The innermost block 184 of each assembly inwardly supports compressionspring 200 which bears against inner surface 202 of actuator bar 190,continually urging actuator bar 190 toward an inner, lug-down position.Actuator bar 190 is forced outward by cam 204. Cam 204 pushes againstcam followers 206 mounted on pins 208 in the inner ends of actuator bars190. Cam 204 is rotatably mounted on pins 210 in a position to engagecam followers 206 which are located on the inner ends of actuator bars190. Cam 204 is mounted on a pintle pin 210 which is fixed centrally onrack 180. A sprocket gear 212 is connected to the pintle pin 210 abovecam 204. Sprocket gear 212 and cam 204 are interconnected by a one-waydrive mechanism, such as a ratchet 214, so that gear 212 will turn cam204 only when the sprocket gear 212 is turned in the direction shown byarrows 216.

Turning of sprocket gear 212 is effected when gear 212 moves acrossteeth 222 in housings 220, which housings are fixed to rack 172 nearouter ends thereof. As shown best in FIG. 8, housings 220 are connectedon opposite lateral sides of the racks 172 so that gear 212 and cam 204are turned in the direction of arrows 216 every time racks 172 and 180are moved to an extreme outward position from the centered position. Therelationship of teeth 222 to gear 212 is such as to turn can 204one-quarter revolution upon each actuation. Thus, if cam 204 is in theposition shown in FIG. 10 with bars 190 forced outward and lugs 24 inthe up position, moving carriage 22 to the right, which is withdrawingshuttle 22 toward the centered position on the platform 20, has noeffect on cam 204, since that movement moves gear 212 across teeth 222in a direction causing clockwise rotation of gear 212 with a resultingslippage of the ratchet 214. Therefore, the cam position is undisturbedand the lug position also remains unchanged. That is the mode ofoperation in which a load is drawn to a centered position on theplatform 20. As shuttle 22 is driven to an extreme extended positionfrom platform in either direction, gear 212 is moved across teeth 222 ina manner which turns gear 212 in a direction of arrow 216, causing cam214 to be rotated 90 from the position shown in FIGS. 9 and 10, andallowing bar 190 to be driven inwardly by spring 200, thus, drawing lugs24 downward to a loadpassing position. The position of the lugs 24 ischanged, either from a down to an up or from an up to a down positioneach time shuttle 22 is driven to a maximum displacement from platform20 in either direction from a centered position.

To insure the correct engagement of teeth 222 and gear 214, adjustingscrews 224 are provided in housing 220. To insure that cam operationtakes place precisely at the end of outward strokes, adjusting screws226 are provided to longitudinally adjust the position of teeth 222 withrespect to rack 172.

As generally shown in FIG. 11, a central computer 230, which controlsthe entire warehouse operation and which is remote from thestacker-retriever 2, is programmed to control sequential operations ofthe stacker-retriever 2. Computer 230 has memory devices which store theparticular location of the stackerretriever mast and platform. Thecomputer 230 then signals the stacker-retriever 2 to move the platformto another location and the carrier 22 of the platform 20 to cycle tothe left or to the right. The instructions from the computer are sentacross a control wire 231 in the form of digital pulses which are pickedup by pickup brushes 232 described in detail in FIG. 2A. The pickupbrushes 232 transfer the digital pulses to a switching device 234. Afirst coding pulse opens circuit 236 to horizontal counter controlcircuit 240. The next sequence of pulses passing through the switchingdevice 234 sets the horizontal coun-er in control circuit 240 to presetthe next horizontal position of the stacker 2.

The next series of pulses from computer 230 through line 231 is a codedsequence which closes the switch to the line 236 and which opens aswitch to line 238. The next sequence of pulses presets the counter invertical counter control circuit 242 to determine the vertical locationof the platform 20. The next series of pulses is a coded signals whichcloses the switch to line 238 and opens a switch to line 244 which setsup the carrier drive circuit 246 for a left or right drive sequence.

As soon as a drive signal has been received by stacker drive 246, thatinformation is communicated to the horizontal and vertical countercontrol circuits 240 and 242 through lines 248 and 249. A startsignal'is generated in the counter control circuits 240 and 242. Signalsare passed through lines 250 and 252 to start the operation of variableoutput controls 254 and 256.

Because the mast is very tall, acceleration of its carriage is verysignificant in that rapid accelerations or decelerations may causewhipping of the mast which produces unwarranted forces in the carriage 6and rails 8. Acceleration control of the platform 20 is not as critical,but it is important that the platform 20 accelerate and decelerate at acontrolled rate. It is especially important that platform 20 neitherdownwardly accelerate nor upwardly decelerate at speeds sufficient toallow the loads to float.

In a preferred form of the invention, variable output controls 254 and256 are very slow speed motors with a predetermined output speed thatare movable slowly between predetermined maximum angular displacementsand which are stoppable at those displacements and at a zero pointbetween the two maximums. Stopping may be controlled by positionswitches such as the telemetering switches shown in FIGS. 3 and 4 andschematically designated in FIG. 11 as direction telemetering devices258 and 259.

Variable output controls 254 and 256 change the positions of swashplates 258 and 259 in variable displacement pumps 260 and 262 which arecontinuously driven by electric motors 264 and 268. According to thesetting of swash plate 258, pump 260 supplies hydraulic fluid underpressure in lines 270 and 272 to drive hydraulic motor 274. The motor inturn operates the horizontal drive 276 which moves mast carriage 278 (6in FIG. 1) along the tracks. Horizontal transducer 280 produce pulseswhich are delivered to horizontal counter control circuit 240 to stepthe counter toward the zero point. Direction telemetering device 258 hasan input to counter 240 so that pulses produced by the rotary transducer280 are added or subtracted from the counter as appropriate from thedesired direction of travel. Alternatively, the rotary transducer mayproduce pulses differentiated according to direction which aredistinguishable by the counter. As the counter approaches the zeropoint, at some predetermined time, a slow or stop signal is provided inline 250 to variable output control 254. The latter decreases the angleof the swash plate and finally places the swash plate in a zero outputposition. When the zero output position is noted by the directiontelemetering equipment 258, current is provided to null leakage control282 to open valve 284 so that no pressure differential is provided tomotor 274. In addition to being a solenoid valve, valve 284 may be ahigh pressure release valve so that high pressure differential betweenlines 270 and 272 is relieved. When the appropriate point is reached,disc brake 286 is set, locking horizontal drive 276. Additionally,caliper brakes not shown may be clamped on the rail. Should the deviceoverrun the zero setting, the circuit automatically employs the overrunin the counter to correct the position back to zero.

Concurrently with the mast being set at the proper position, theplatform is set at the proper vertical position by operating thehydraulic motor 290 until the vertical rotary transducer 292 hasproduced sufficient pulses to return vertical counter 242 to its zerosetting,

When both horizontal counters and vertical counters have achieved theirzero settings, signals are provided through lines 294 and 296 to enablecarrier drive 246 to perform its preprogrammed left or right cycle. Uponcycling, the shuttle 22 automatically picks up or discharges a load,depending only upon the physical position of lugs 24' when the shuttle22 is driven into its maximum position of displacement from the platform20.

While the horizontal and vertical positioning is being affected,switching device 234, is receiving the next pulse train for programmingthe next movement of the stacker-retriever. As soon as carrier drive 146has been cycled, a signal is given through line 298 to begin the nextstacker sequence.

As can be seen from the remainder of the schematic diagram, the powerand control train of the vertical drive for the platform is similar tothe power and control train for the horizontal drive of the mastcarriage.

Shuttle drive is affected by a reversible electrical motor which drivesin a first direction to a maximum point controlled by limit switches onthe shuttle 22 or accu mulative angular displacement switch on the motordrive shaft and then drives in the other direction a similar amount sothat the carrier is centered on the 6 platform after cycling. Thevertical and horizontal tle 22 is centered on the platform 20 due tointerlocking of the controls in a known manner. Because of theinterlocking controls, the shuttle drive may be operated only when thevertical and horizontal counters are stationary at a predeterminedreading. Primarily three operating instructions are provided to thestacker-retriever 2 by the computer 230. The horizontal counter and thevertical counter are reset away from zero according to the respectivehorizontal and vertical components of the distance to be traveled fromthe present location to the next location of the stackerretrieversplatform. Additionally, the computer 230 instructs the shuttle 22 bypresetting circuits for shuttle cycling to the right or to the left ofthe platform 20. When these three instructions have been provided, a gosignal is generated, the horizontal and vertical drives operateconcurrently for as long as necessary, accelerating and thendecelerating as the respective counters approach zero. As soon as bothcounters are on zero for a brief predetermined time delay to insureagainst overrun, the carrier 22 is cycled with respect to the platform20. The delivery or retrieval mode of operation of the shuttle lugs 24is not controlled by the computer. The delivery or retrieval mode of theshuttle lugs 24 is simply a mechanical function which automaticallychanges the position of the lugs 24 upon extreme displacement of theshuttle 22 from the platform 20 as was previously described in detail. I

While the invention has been particularly shown an described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

What we claim is:

1. In a warehousing system apparatus having an elongated aisle, astorage rack with a face parallel to the aisle, a plurality of loadholding elements in the rack adjacent to and accessible to from theaisle, a track mounted adjacent the storage rack in the aisle, a mast onthe track for moving along the aisle parallel to the face of the rack,horizontal propelling means connected to the mast for moving the mast inthe aisle, a platform mounted on the mast for vertical movement thereon,vertical propelling means connected to the mast and to the platform fordriving the platform up and down the mast, a shuttle movably mounted onthe platform, transverse propelling means connected to the shuttle andto the platform for moving the shuttle into and out of the rack, wherebyloads within the rack are transferred to the platform by the shuttle,and whereby the loads are relocated within the aisle by movement of themast and platform, the improvement comprising:

fluid supply means mounted on the mast,

fluid pressure source means mounted on the mast and connected to thefluid supply means, the fluid pressure source means having electricmotor means mounted on the mast and connected to a source of electricalpower, fluid pump means connected to the electric motor means and to thefluid supply, and first and second fluid delivery line means connectedto the pump means,

first and second fluid pressure control means connected to the fluidpressure source means for respectively controlling pressure in the firstand second delivery line means,

first hydraulic motor means connected to the first delivery line means,

first mechanical driving means connected to the first hydraulic motormeans and to the mast for driving the mast along the aisle in responseto pressure applied in the first delivery line means,

second hydraulic motor means connected to the second delivery linemeans, and

second mechanical driving means connected to the second hydraulic motormeans, to the mast means and to the platform for driving the platformalong the mast in response to fluid pressure in the second delivery linemeans, said control means comprises control motor means having shaftmeans connected to the pump means for controlling the output thereof andfurther comprising;

indicator means connected to the shaft means for indicating the positionof the shaft means and therefore the direction in which fluid pressuredifforential exists in first and second delivery line meansinterconnecting the motor means and the pump means,

the indicator means further comprising cam means connected to the shaftmeans and switch means adjacent the cam means for operation thereby forsensing the position of the cam means and hence the shaft means.

2. Warehousing system apparatus of claim 1 wherein:

first fluid pressure control means comprises a horizontal drive countercontrol means,

a horizontal drive variable output control means connected to thehorizontal drive counter means and connected to the fluid pressuresource means for controlling fluid pressure in the first delivery linemeans in response to the condition of the horizontal drive countermeans, and

pulsing means connected to the mast and to the aisle for producingpulses as the mast moves horizontally in the aisle and connected to thehorizontal drive counter means for supplying pulses thereto for changingcondition thereof, and wherein the second fluid pressure control meanscomprises a vertical drive control circuit means,

a vertical drive variable output control means connected to the verticaldrive counter means and connected to the fluid pressure source means forcontrolling fluid in the second delivery line means in response to thecondition of the vertical drive counter means, and

pulsing means connected to the mast and to the platform for producingpulses as the platform moves vertically on the mast and connected to thevertical drive counter means for supplying pulses thereto for changingcondition thereof.

3. Warehousing system apparatus of claim 2 wherein the electric motormeans and pump means comprise:

first and second electric motors respectively connected to first andsecond pumps, and wherein the horizontal and vertical drive variableoutput control means are interconnected to the first and second pumps,respectively.

4. The warehousing system apparatus of claim 3 further comprising:

first and second direction indicator switches connected to respectiveinterconnections between horizontal and vertical drive variable outputcontrol means and the first and second pumps for indicating positions ofthe interconnections and output conditions of the pumps. 5. Thewarehousing system apparatus of claim 4 wherein:

the first and second direction indicator switches are connected to therespective variable output control means transmitting direction signalsto the variable control means.

6. The warehousing system apparatus of claim 4 wherein:

the first and second direction indicator switches further are connectedrespectively to the horizontal and vertical drive counter controlcircuit means to provide direction indicate relative movement betweenthe mast and aisle and between the platform and mast.

7. The warehousing system apparatus of claim 4 wherein the firstdelivery means comprises:

wherein the mast further comprises:

a plurality of roller means for supporting the mast on the track, withmast movement limited to longitudinal reciprocation therealong, andwherein the horizontal propelling means comprises pivot means connectedto the mast,

lever means connected to the pivot means,

axle means connected to the lever means at a location remote from thepivot means,

driving wheel means connected to the axle means,

and

weight means mounted on the lever means remote from the pivot means, forurging the drive wheel means into frictional engagement with a floorsurface of the aisle means.

9. The warehousing system apparatus of claim 8 wherein the weight meanscomprises:

hydraulic motor means and reductiongear means operatively connected tothe driving wheel means for moving the mast along the track.

10. The warehousing system apparatus of claim 1 wherein the improvementfurther comprises:

lugs mounted on the shuttle for movement with respect thereto between anupper load-engaging position and a lower load-passing position,

lug control means connected to the shuttle and to the lugs forpositioning the lugs with respect to the shuttle and movement directionresponsive means connected to the shuttle, platform and means for movingthe lug control means and changing position of the lugs upon completionof each outward movement of the shuttle with respect to the platform.

mm f UNH'HjED STATES EAEEEE @EEEE Inventofls) K.A.Richens;S.C.,Grove-r*; J .K;-All;red; J..H'.-Shook It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

PLEASE NOTE THAT THE TITLE OF THE INVENTION SHOULD READ f'DRIv-E MEANSFOR A VEHICLE IN A WAREHOUSING' APPARATUS NOT- "DEVICE. u H o ASPRINTED;

Signed and sealed this 29th day of May 19, 1975.

(SEAL) I I Attest:

ED WARD M.F-LE TQHER, JR. 1 7 ROBERT GOTTSCHAL'K AEt 'stl ng qfflcer A ICommissioner of Patents

1. In a warehousing system apparatus having an elongated aisle, a storage rack with a face parallel to the aisle, a plurality of load holding elements in the rack adjacent to and accessible to from the aisle, a track mounted adjacent the storage rack in the aisle, a mast on the track for moving along the aisle parallel to the face of the rack, horizontal propelling means connected to the mast for moving the mast in the aisle, a platform mounted on the mast for vertical movement thereon, vertical propelling means connected to the mast and to the platform for driving the platform up and down the mast, a shuttle movably mounted on the platform, transverse propelling means connected to the shuttle and to the platform for moving the shuttle into and out of the rack, whereby loads within the rack are transferred to the platform by the shuttle, and whereby the loads are relocated within the aisle by movement of the mast and platform, the improvement comprising: fluid supply means mounted on the mast, fluid pressure source means mounted on the mast and connected to the fluid supply means, the fluid pressure source means having electric motor means mounted on the mast and connected to a source of electrical power, fluid pump means connected to the electric motor means and to the fluid supply, and first and second fluid delivery line means connected to the pump means, first and second fluid pressure control means connected to the fluid pressure source means for respectively controlling pressure in the first and second delivery line means, first hydraulic motor means connected to the first delivery line means, first mechanical driving means connected to the first hydraulic motor means and to the mast for driving the mast along the aisle in response to pressure applied in the first delivery line means, second hydraulic motor means connected to the second delivery line means, and second mechanical driving means connected to the second hydraulic motor means, to the mast means and to the platform for driving the platform along the mast in response to fluid pressure in the second delivery line means, said control means comprises control motor means having shaft means connected to the pump means for controlling the output thereof and further comprising; indicator means connected to the shaft means for indicating the position of the shaft means and therefore the direction in which fluid pressure difforential exists in first and second delivery line means interconnecting the motor means and the pump means, the indicator means further comprising cam means connected to the shaft means and switch means adjacent the cam means for operation thereby for sensing the position of the cam means and hence the shaft means.
 2. Warehousing system apparatus of claim 1 wherein: first fluid pressure control means comprises a horizontal drive counter control means, a horizontal drive variable output control means connected to the horizontal drive counter means and connected to the fluid pressure source means for controlling fluid pressure in the first delivery line means in response to the condition of the horizontal drive counter means, and pulsing means connected to the mast and to the aisle for producing pulses as the mast moves horizontally in the aisle and connected to the horizontal drive counter means for supplying pulses thereto for changing condition thereof, and wherein the second fluid pressure control means comprises a vertical drive control circuit means, a vertical drive variable output control means connected to the vertical drive counter means and connected to the fluid pressure source means for controlling fluid in the second delivery line means in response to the condition of the vertical drive counter means, and pulsing means connected to the mast and to the platform for producing pulses as the platform moves vertically on the mast and connected to the vertical drive counter means for supplying pulses thereto for changing condition thereof.
 3. Warehousing system apparatus of claim 2 wherein the electric motor means and pump means comprise: first and second electric motors respectively connected to first and second pumps, and wherein the horizontal and vertical drive variable output control means are interconnected to the first and second pumps, respectively.
 4. The warehousing system apparatus of claim 3 further comprising: first and second direction indicator switches connected to respective interconnections between horizontal and vertical drive variable output control means and the first and second pumps for indicating positions of the interconnections and output conditions of the pumps.
 5. The warehousing system apparatus of claim 4 wherein: the first and second direction indicator switches are connected to the respective variable output control means transmitting direction signals to the variable control means.
 6. The warehousing system apparatus of claim 4 wherein: the first and second direction indicator switches further are connected respectively to the horizontal and vertical drive counter control circuit means to provide direction indicate relative movement between the mast and aisle and between the platform and mast.
 7. The warehousing system apparatus of claim 4 wherein the first delivery means comprises: first parallel hydraulic lines between the first pump means and the first hydraulic motor means, and wherein the apparatus further comprises first valve means between the first parallel lines, first leakage control means connected to the direction indicator means and connected to the first valve means for operating the first leakage control means and opening the first valve means when the horizontal variable output control controls the pump at the middle null position.
 8. The warehousing system apparatus of claim 1 wherein the mast further comprises: a plurality of roller means for supporting the mast on the track, with mast movement limited to longitudinal reciprocation therealong, and wherein the horizontal propelling means comprises pivot means connected to the mast, lever means connected to the pivot means, axle means connected to the lever means at a location remote from the pivot means, driving wheel means connected to the axle means, and weight means mounted on the lever means remote from the pivot means, for urging the drive wheel means into frictional engagement with a floor surface of the aisle means.
 9. The warehousing system apparatus of claim 8 wherein the weight means comprises: hydraulic motor means and reduction gear means operatively connected to the driving wheel means for moving the mast along the track.
 10. The warehousing system apparatus of claim 1 wherein the improvement further comprises: lugs mounted on the shuttle for movement with respect thereto between an upper load-engaging position and a lower load-passing position, lug control means connected to the shuttle and to the lugs for positioning the lugs with respect to the shuttle and movement direction responsive means connected to the shuttle, platform and means for moving the lug control means and changing position of the lugs upon completion of each outward movement of the shuttle with respect to the platform. 